We used the SunSpider suite of JavaScript tests to determine which browser was the quickest, and the Safari 4 beat every browser in terms of speed, on both a PC running Windows XP SP2, and a Mac running OS X 10.5.6 with all updates applied.

Below are the actual figures if you want to see how all seven browsers scored against each other, but for quick reference we determined on a PC that Safari was a whopping 42 times faster than Internet Explorer 7, just over six times faster than Internet Explorer 8, 3.5 times faster than Firefox 3, and 1.2 times faster than Google Chrome. Here's Safari versus the rest, excluding IE 7:

Add IE 7's results to the PC graph and witness the shocking truth. These are results from a PC with a 2.1GHz Intel Core 2 Duo:

We'll be bringing you a full hands-on report with the new features of Safari very soon, but you can download it yourself already here.

Update: Some commenters have suggested we should have tested Opera's latest alpha release of Opera 10, as it features an improved rendering engine. We just benchmarked it and it scored 3706ms, putting it in fifth position on the PC, only marginally faster than Opera 9.6.